JEE Main2006MathematicsApplication of DerivativesActual
If x is real, the maximum value of 3 x^2+9 x+17 3 x^2+9 x+7 is
Options
- A1/4
- B41
- C1
- D17/7
Correct answer
B. 41
Step-by-step solution
y= 3 x^2+9 x+17 3 x^2+9 x+7 3 x^2(y-1)+9 x(y-1)+7 y-17=0D 0 x is real 81(y-1)^2-4 x 3(y-1)(7 y-17) 0 (y-1)(y-41) 0 1 y 41